Sequence ID colourscheme is not applied when view restored from project

The SequenceID colour scheme is not applied to a view when restored from project.

[~gmungoc] suggests a quick patch for this in JAL-3127 (https://issues.jalview.org/browse/JAL-3127?focusedCommentId=21683&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-21683)

in Jalview2XML.loadViewport:
    for (SequenceGroup sg : viewport.getAlignment().getGroups())
    {
      ColourSchemeI cs = sg.getColourScheme();
      if (cs != null)
      {
        cs = cs.getInstance(viewport, sg);
        sg.setColourScheme(cs);
      }
    }